The invention relates to a device by means of which to align bottles provided with reference moldings, for use with rotary type labeling machine. High speed labeling machines conventionally afford a revolving platter or turntable incorporating a plurality of equispaced peripheral dishes on which bottles are carried and positioned for labeling. In operation, the revolving turntable is rotated through one or more labeling stations, at which single labels drawn from a magazine are gummed and transferred to the bottle, respectively.
The dishes, onto which the unlabeled bottles are transferred by a conventional star wheel conveying device, are in turn individually rotatable about their vertical axes.
Each label must be applied to the respective bottle in alignment with a reference, embodied as a notch or projection offered by the lateral surface of the bottle itself, generally at bottom; in short, the label must be pasted to the bottle at a prescribed position in relation to the notch, or other molded reference.
The prior art embraces two methods of aligning the bottle in relation to the gummed label, of which one involves effecting the alignment as the bottle passes through the star wheel device, prior to its entry onto the turntable. In this first method of alignment, a photocell is used to operate friction or gripping means that stop and hold the rotating bottle on arrival at a given angular position.
The second method, which is entirely mechanical and consists similarly in positioning the bottle during its passage through the star wheel entry station, makes use of a mechanical device that engages the bottle directly when in a predetermined position. In both the electrical and mechanical systems thus outlines, one has the drawback that the bottle is transferred from the star wheel to the turntable without the aid of any constraining or clamping action, and is therefore free to rotate about its own axis; the result is that correct alignment of the bottle, hence correct positioning of the label, can no longer be guaranteed.
The object of the present invention is to overcome the drawbacks aforementioned, and in particular, to effect alignment of the bottle in a position such as will disallow further movement in relation to the labeling components and thus ensure faultless positioning of the label in relation to a reference incorporated into the bottle.